The present disclosure relates to the field of orthodontics. More specifically, the present disclosure relates to self-ligating brackets.
Orthodontic treatment often involves at least a combination of an arch wire and brackets and/or buccal tubes that are used to secure the arch wire to the teeth of the patient. The arch wire is made of a resilient material that, if bent or deformed, will return to its previous shape. Dental malocclusions are treated by securing the arch wire to the patient teeth which are brought into a post-treatment alignment as the arch wire returns to its original shape. The corrective forces are transferred from the interactions between the arch wire and the arch wire slot of the bracket, through the bracket to the tooth.
Traditionally, brackets are secured to the teeth of a patient and the brackets have an arch wire slot within which the arch wire is received. Elastomeric ligatures secure the arch wire within the arch wire slot of the bracket. Self-ligating brackets include a built in mechanical ligature which eliminates the need for separate elastomeric ligatures to secure the arch wire to the bracket. Self-ligating brackets typically use a sliding and/or rotating clip or door that moves relative to the bracket body to occlude the arch wire slot.
Self-ligating brackets are available as “active” brackets or “passive” brackets, which describe the way in which the arch wire may interact with the clip. Active self-ligating brackets include a clip in which an end or portion extends into an edgewise slot and resiliently applies a seating force against an arch wire in the facial-lingual dimension. The active self-ligating bracket retains the arch wire in the slot due to the mechanical strength of the clip itself. Active self-ligating brackets provide more control of the interactive forces between the clip and the arch wire, but can increase friction between the arch wire and the clip, which may reduce the transfer of this force to the tooth.
Passive self-ligating brackets include a clip that extends across and beyond the arch wire slot and is fixed or restrained against movement in the facial-lingual dimension. The passive self-ligating bracket, when closed, effectively forms a tube defined by the slot and the clip within which an arch wire with a diameter smaller than a diameter of the formed tube can slide. For this reason, in some applications, the clip of a passive self-ligating bracket is called a door.